Angle brackets are used in the making of tools and quality control fixtures to support a wide variety of items on a tool bed or other fixture. Angle brackets are typically made of steel or iron for strength and durability. For example, U.S. Pat. No. 4,489,500 to Valet, discloses a multipurpose angle bracket made of steel that is formed by either casting or by mechanical assembly and welding. U.S. Pat. No. 4,968,012 to Haddad, discloses a workpiece holding apparatus used to check part dimensions. The Haddad patent discloses a base that is cast as a single integral element and subsequently machined to a generally cubical configuration.
A problem with such prior art angle brackets is that metal brackets add to the weight of the tooling. They also require machining and finishing steps that add to the cost of manufacturing. Metal brackets are also costly to replace.
Angle brackets are used to support tool elements that are designed to withstand normal loads applied in a predetermined manner. If metal angle brackets are subjected to a side impact or other unintended load, they may become distorted or bent and the force of impact may be transferred to the tool necessitating repair of the tool. If a substantial unintended load is applied to the tool, damage may be caused to expensive tooling parts supported by the angle bracket.
The electrical conductivity of metal angle brackets can cause problems if there is an electrical malfunction of the equipment to which the bracket is attached. Metal angle brackets do not isolate tooling elements from the base and will not prevent short circuiting through the angle brackets.